Various types of metering devices are known. One example is the electronic postage meter as, for instance, described in U.S. Pat. No. 3,978,457 to Check et al. As is well known, postage meters include an ascending register, that stores a running total of all postage dispensed by the meter, and a descending register, that holds the remaining amount of postage credited to the meter and that is reduced by the amount dispensed each time postage is printed by the meter. Because U.S. Postal Service regulations requires that postage be paid in advance, it had traditionally been required that the user of a postage meter periodically present the meter to a Postal Service employee for recharging. At the time of recharging, the user pays to the Postal Service an amount of postage to be credited to the meter and the postal employee credits or recharges the meter that amount paid by increasing the setting of the descending register by that amount. As the meter was used to dispense postage (by printing meter stamps on envelopes or labels), the setting of the descending register was reduced until either the meter was again recharged, or the setting reached zero or a pre-established figure near zero, at which point the meter was automatically locked, and thereby prevented from printing further meter stamps, until the meter was recharged. This locking feature is sometimes referred to as a "credit lockout", signifying that the meter is disabled upon exhaustion of the previously credited amount.
Another method of recharging postage meters while still satisfying Postal Service regulatory requirements has been developed and is described, for example in U.S. Pat. No. 3,792,446 to McFiggans et al., entitled "Remote Postage Meter Resetting Method". As described in the McFiggans et al. patent, a postage meter includes a combination lock that inhibits recharging of the meter. The required combination randomly changes each time the lock is opened. The user of the postage meter maintains an account with a credit balance. A central data center maintains a record of the user's account. When the user wishes to recharge the meter, he places a telephone call to the data center. The data center, using a voice answer back system, obtains identifying information from the user, verifies the information and checks to see that the user has sufficient funds in his account to cover the postage to be credited to the meter. The data center then provides a combination to the user that will allow the meter to be credited with a pre-determined amount of postage. At the same time, the center debits that amount from the user's account. The user enters into the postage meter the combination received from the data center. The meter is then unlocked so that the user can increment the descending register by the predetermined amount.
The remote recharging method described by McFiggans et al. was implemented with great success. A subsequent adaptation and improvement of this method is described in U.S. Pat. No. 4,097,923 to Eckert et al. The system of Eckert et al. is operable with a microcomputer controlled postage meter and allows the user to select a variable amount of postage with which the meter is to be credited. In the Eckert et al. system, the user advises the data center of the selected amount of postage and the data center provides a combination that reflects the selected amount of postage. The user enters the selected amount and the combination into the meter, which makes its own calculation of a combination into the meter, which makes its own calculation of a combination based upon the entered amount. The calculated combination is compared to the entered combination and if the two are consistent, the descending register is incremented by the entered amount.
In contrast to the U.S. Postal Service, the postal authorities of some foreign countries do not require prepayment of postage in all cases. In those countries, postage meters are not required to have the credit lockout feature. Postage meters of the type previously described herein may be adapted for use in those countries by, for example, eliminating the mechanism that locks the meter when the descending register reaches its minimum reading, or by omitting the descending register entirely, or by setting the descending register to a very high reading, or by allowing the user to reset the descending register whenever necessary. However, since postage is not prepaid, arrangements must be made for payments after the fact. Typically these arrangements include presentation of the meter for reading by a postal employee with payment in response to billing based on the meter reading.
A postage meter, in many respects, is equivalent to a currency printing device, it is a principle concern of the respective postal authorities that the manufacturer keep track of all meters in use and to be able to identify lost or stolen postage meters. In order to attempt to prevent their unauthorized use, U.S. Pat. No. 5,243,654 to Hunter describes a time lockout system which engages after the elapse of a given period of time. Hunter describes (a) a metering system which includes a dispensing or printing system for dispensing an accounting quantity of postage; (b) an accounting system for updating and storing information that represents the amount of postage dispensed by the printing mechanism; (c) a user interface system, e.g., keyboard and display, connected to the accounting mechanism for outputting the stored information; (d) a non-volatile memory for storing a time deadline; (e) a calendar clock mechanism for providing a signal that represents the current date; (f) a locking mechanism connected to the printer mechanism, the calendar clock mechanism and the non-volatile memory unit, for disabling the printing mechanism when the current date is not earlier than the time deadline; and (g) a deadline reset mechanism connected to the storage mechanism for extending the stored time deadline.
The deadline reset mechanism requires receiving a verification signal and comparing the verification signal with the stored accounting information. The deadline reset mechanism extends the stored time deadline if the verification signal is in accordance with the stored accounting information. The verification signal includes a deadline-extending combination to the user. The combination is inputted into the meter and results in extending the stored time deadline. The system as presented in Hunter presents several issues in the international marketplace. One such issue is the need for a data center and for meters to have remote resetting capability. In certain regions of the international market, it is logistically difficult to provide the necessary infrastructure to support remote meter resetting. Another concern with the Hunter system is related to the condition of exposing the accounting register to a possible fault condition as a result of requiring the entry of a deadline-extending combination necessitating access to the secure non-volatile accounting memories.